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Antecedentes: Los manglares están en constante transformación por procesos ecológicos y antrópicos. El uso de imágenes de satélite a través de la teledetección ayuda a entender y estudiar la dinámica y los cambios espacio temporales de los manglares. Pregunta: ¿Cuál es la dinámica de la cobertura del manglar en el municipio de Alvarado usando una serie de tiempo larga? Descripción de datos: Todas las imágenes disponibles de Landsat. Sitio y años de estudio: El municipio de Alvarado, Veracruz desde el año 1985 hasta el año 2021. Métodos: Calculamos y estimamos el NDVI para todas las imágenes satelitales Landsat a una resolución espacial de 30 m. Identificamos los patrones en la dinámica del manglar con base en la trayectoria anual usando una serie de tiempo larga. Resultados: El promedio anual del NDVI del manglar incrementó linealmente durante el periodo de estudio. El 50 % de la cobertura del manglar (118 km2) está conformada por áreas sin perturbación desde el inicio del periodo estudiado, acumulando entre 25 y 36 años sin cambio. Las áreas con mayor biomasa representan el 0.2 % de la cobertura del manglar en el municipio. Identificamos áreas con buena calidad en la cobertura del manglar los cuales son sitios prioritarios para la conservación. Conclusiones: El municipio de Alvarado requiere urgentemente planes y acciones para conservar las zonas con mayor calidad de manglar que aún persisten. Estas zonas deberían protegerse por su importancia para la conservación de la biodiversidad y porque están amenazadas por la expansión urbana y agrícola.

The Neotropical realm hosts some of the Earth’s most species-rich biodiversity hotspots, with vascular epiphytes significantly contributing to this diversity. However, many regions of the Neotropics where epiphytic species of restricted distribution are reported coincide with threatened ecosystems, such as the tropical montane cloud forest. Moreover, epiphytes may be especially vulnerable to land use and climate change impacts due to their dependence on host trees. We assessed the conservation status of vascular epiphytes in the Neotropics for the families that represent over 80% of the global epiphyte diversity (Araceae, Bromeliaceae, Orchidaceae, Piperaceae, and Polypodiaceae) and identified geographical centers of accumulation of threatened epiphyte species. We gathered information from free-access web repositories, specific epiphytic plant databases, and scientific and grey literature. We assessed the extinction risk of 11,446 epiphyte species following IUCN Red List guidelines, using Criterion B (geographic range size). We found nearly 60% (6,721 species) to be threatened, with 1,766 critically endangered (CR), 3,537 endangered (EN), and 1,418 vulnerable (VU). The threatened species are mainly found in the centers of endemism of vascular epiphytes in Central America, the northern Andes, and the Atlantic Forest. Our study emphasises that the centers of threatened species largely coincide with diversity hotspots, highlighting epiphytes as an especially vulnerable group that requires urgent conservation actions.

Ceratozamia morettii,C. brevifronsandC. tenuisare cycads considered endangered in montane forests in the center of Veracruz state. However, the amount of theoretical and empirical information available on the historical distribution of these species and how they could be affected in the future by the effects of climate change is still limited. Our objective was to generate information on the spatial distribution of the species since the last glacial maximum, present and future. To map the spatial distribution of species, we created a potential distribution model for each species. The spatial data used for the models included 19 bioclimatic data variables in the present, at the last glacial maximum using two models (CCSM4 and MIROC), and in the future (2080) using two models of the RCP 8.5 scenario of climate change (HadGEM2-CC and MIROC5). We found that each species occupies a unique ecoregion and climatic niche.Ceratozamia morettiiandC.tenuishave a similar pattern with an expansion of their distribution area since the last glacial maximum with the larger distribution area in the present, and with a projected reduction in their distribution under future climatic conditions. ForC. brevifrons,we also showed an increase in their distributional area since the last glacial maximum and we showed that this expansion will continue under future climatic conditions when the species will reach its maximum distributional area. Projections about the future of these endemic cycad species show changes in their habitat highlighting that temperate zone species will face imminent extinction if no effort is made to protect them. On the other hand, the tropical climate species will apparently be favored.

Background: Tropical montane forests are important reservoirs of carbon and biodiversity but are threatened by deforestation and climate change. It is important to understand how forest structure and aboveground biomass change along gradients of elevation and succession. Questions: What are the interactive effect of elevation and two stages of succession on forest structure parameters? Studied species: Tree communities. Study site and dates: Cofre de Perote, Veracruz, Mexico. August to December 2015. Methods: We studied four sites along an elevational gradient (500, 1,500, 2,500, and 3,500 m). At each elevation and each forest type, we established five 20 × 20 m plots (n = 40 plots). Within each plot, we measured stem density, mean diameter at breast height (dbh), and tree height and derived basal area and aboveground biomass (AGB). Results: AGB peaked at 2,500 m and was significantly related to elevation and succession, with higher values in old-growth forests than in secondary forests at higher altitudes. Lower values of mean dbh and basal area were found at higher elevations. At the lowest elevation, both successional stages had the same values of stem density and AGB. At both lower elevations, secondary forests had higher values of dbh and basal area. There were high biomass stocks in the old-growth forest at 2,500 and 3,500 m. Conclusions: Old-growth forests at higher elevations are threatened by deforestation, consequently these remaining fragments must be preserved because of their storage capacity for biomass and their ability to mitigate climate change.

The scientific work of Alexander von Humboldt was influenced by his interaction with the diversity and natural wealth of the Neotropics. He proposed that climate determines plant diversity along elevational gradients based on his observations. Here, we evaluated the most prominent climate-based hypotheses in explaining plant diversity along an elevational gradient that Humboldt himself visited during his journey across Mexico. Specifically, we examined how climatic variables and forest-use intensity affected species richness and phylogenetic structure of major angiosperm life forms (trees, shrubs, epiphytes, herbs and lianas) along the Cofre de Perote mountain, Veracruz, Mexico. We analysed species richness and phylogenetic structure of angiosperms at eight sites between 30 to 3500 m a.s.l. We estimated the phylogenetic structure using a mega-phylogeny of angiosperms and the abundance-weighted net relatedness index. We considered multiple environmental factors’ direct and indirect effects by applying a piecewise structural equation modelling approach. Each life form responds differently to the environmental variables included in our model; however, it is observed that temperature is the main predictor of the taxonomic and phylogenetic diversity of the angiosperms studied, both when the different life forms are grouped and separated. Potential evapotranspiration and precipitation are variables that also influence some life forms’ diversity, especially taxonomic diversity. The forest-use intensity negatively affected only the taxonomic diversity of trees. These results highlight the influence of studying the different life forms of angiosperms in diversity gradient models and show the great influence that temperature has in conjunction with other environmental variables to promote the taxonomic and phylogenetic diversity of plant communities. Given the current global environmental crisis, an integrative biogeographically oriented vision based on Humboldt’s method is necessary. Honouring the work of Humboldt and continuing his legacy demands more research to understand the causes behind elevational diversity gradients.

Se presenta un estudio sobre recolección de productos forestales no maderables (PFNM) en la población de El Escobillo, Veracruz, México, y zonas adyacentes del Parque Nacional Cofre de Perote (PNCP). Se registraron 70 especies (45 plantas vasculares, dos briofitas y 23 hongos), clasificadas en siete categorías de uso, destacando el comestible (31) con el mayor ingreso por venta, seguido por el medicinal (21), el de leña y el ceremonial por volumen recolectado para autoconsumo y el artesanal para la venta. De acuerdo con la normatividad mexicana (NOM-059-SEMARNAT-2010), en el área de estudio el hongo pananaca, los hongos cochinitos y la palma chimale se encuentran en la categoría de amenazada y el hongo de perfume está sujeto a protección especial. Se identificaron 33 sitios de recolección ubicados en tres zonas del PNCP y cinco sistemas de manejo. El sistema “montaña” representa la mayoría de los sitios de recolección y especies silvestres, principalmente hongos para venta y autoconsumo. La recolección de PFNM representa un ingreso (sin considerar los egresos) estimado en MXN 943 624 anuales. Es necesario promover la participación de los habitantes del PNCP, como custodios y manejadores de los PFNM en estrategias sustentables, con especial énfasis en la integración de sus conocimientos y formas de organización, así como considerar la colaboración con las organizaciones de la sociedad civil, gobierno, empresas y academia.

Background: The loss of functional keystone species may lead to the loss of key functions in the ecosystem. Few studies so far have addressed the functionality of specific morphological traits of f...

Antecedentes: Las hierbas terrestres son un elemento florístico importante de los bosques tropicales; sin embargo, aún es escasa la investigación centrada en este grupo de plantas. Pregunta: ¿Cuáles son los patrones de distribución de especies de angiospermas herbáceas a lo largo de gradientes de altitud y de perturbación en el Cofre de Perote, centro de Veracruz, México? Especies de estudio: Angiospermas herbáceas terrestres. Sitio de estudio y años de estudio: Vertiente este del Cofre de Perote, centro de Veracruz, México; desde 2012 hasta 2014. Métodos: Establecimos un gradiente altitudinal (40 a 3,520 m), donde realizamos un muestreo florístico en ocho sitios de estudio dentro de pisos altitudinales de aproximadamente 500 m cada uno. Registramos la presencia de angiospermas herbáceas terrestres dentro de 135 parcelas de 20 × 20 m, distribuidas en bosques maduros, degradados, secundarios, así como vegetación azonal. Se analizó la riqueza de especies, la composición florística y luego comparamos los datos resultantes entre los diferentes pisos altitudinales y los grados de perturbación del bosque. Resultados: Se registraron 264 especies de plantas, 31 endémicas de México y tres amenazadas. Esta riqueza representa 5.7 % de la flora de herbáceas angiospermas en Veracruz. Los pisos altitudinales con mayor riqueza de especies fueron 2,500 m (76) y 1,500 m (52). En la mayoría de los casos, los bosques secundarios tuvieron la mayor riqueza de especies en el gradiente altitudinal, mientras que los bosques maduros tuvieron menos especies. Conclusiones: La riqueza de especies observada, incluyendo elementos endémicos, resalta la importancia de esta zona para la conservación de plantas, que se encuentra amenazada por el cambio de uso del suelo. Además, sugerimos que la variación de la vegetación formada por bosques maduros, perturbados y secundarios es aceptable (e inevitable) y puede incluso incrementar la riqueza de especies.

Antecedentes y Objetivos: Los arbustos son un elemento florístico importante de los bosques tropicales; sin embargo, la investigación sobre plantas con esta forma de crecimiento aún es escasa. El objetivo principal de este estudio consistió en analizar la influencia de la elevación y la perturbación en los patrones de distribución y diversidad de los arbustos en la región central de Veracruz, México.Métodos: Se estableció un gradiente elevacional (20-3500 m s.n.m) en la ladera este del Cofre de Perote, donde se realizó un muestreo florístico en ocho pisos elevacionales separados por 500 m cada uno. Registramos la abundancia de arbustos dentro de 120 parcelas de 20 × 20 m, distribuidas en tres hábitats: bosque conservado, perturbado y secundario. Se analizó la riqueza, diversidad y composición florística; además, se compararon los datos resultantes entre los diferentes pisos elevacionales y los grados de perturbación del bosque.Resultados clave: Se registraron 118 especies y 14 morfoespecies de arbustos, lo que representa 8.6% de los reportados para Veracruz. Los fragmentos de bosque en las elevaciones de 500 y 1000 m son los más ricos en número de especies, pero también son los más susceptibles a las perturbaciones humanas. La influencia antrópica sobre estos bosques puede incrementar la diversidad de especies a nivel local, pero al mismo tiempo modifica la composición florística de un hábitat conservado a uno secundario.Conclusiones: El presente estudio es el primero en el Neotrópico en considerar y analizar los arbustos como un grupo individual a lo largo de un gradiente completo utilizando un método de muestreo uniforme y comparable. Esto permitió detectar aquellos fragmentos de bosque conservado, perturbado o secundario que son altamente diversos y susceptibles a los distrubios antrópicos. Estos sitios sirven como zonas estratégicas de amortiguación y refugio de este grupo de plantas, ya que independientemente de la intensidad de su uso, estos podrían y deberían considerarse en futuros planes de conservación en esta región amenazada por la degradación ambiental.

Terrestrial herbs are important elements of tropical forests; however, there is a lack of research on their diversity patterns and how they respond to different intensities of forest-use. The aim of this study was to analyze the diversity of herbaceous angiosperms along gradients of elevation (50 m to 3500 m) and forest-use intensity on the eastern slopes of the Cofre de Perote, Veracruz, Mexico. We recorded the occurrence of all herbaceous angiosperm species within 120 plots of 20 m x 20 m each. The plots were located at eight study locations separated by ~500 m in elevation and within three different habitats that differ in forest-use intensity: old-growth, degraded, and secondary forest. We analyzed species richness and floristic composition of herb communities among different elevations and habitats. Of the 264 plant species recorded, 31 are endemic to Mexico. Both α- and γ-diversity display a hump-shaped relation to elevation peaking at 2500 m and 3000 m, respectively. The relative contribution of between-habitat β-diversity to γ-diversity also showed a unimodal hump whereas within-habitat β-diversity declined with elevation. Forest-use intensity did not affect α-diversity, but β-diversity was high between old-growth and secondary forests. Overall, γ-diversity peaked at 2500 m (72 species), driven mainly by high within- and among-habitat β-diversity. We infer that this belt is highly sensitive to anthropogenic disturbance and forest-use intensification. At 3100 m, high γ-diversity (50 species) was driven by high α- and within-habitat β-diversity. There, losing a specific forest area might be compensated if similar assemblages occur in nearby areas. The high β-diversity and endemism suggest that mixes of different habitats are needed to sustain high γ-richness of terrestrial herbs along this elevational gradient., Open-Access-Publikationsfonds 2017

Questions How do species richness and composition of fern assemblages change with elevation and, within elevational belts, in differently impacted forest habitats? Is there a relationship between fern assemblages and microclimate, both along gradients of elevation and disturbance? Which species are most sensitive to habitat disturbance and microclimatic changes? Location The transect starts at sea level close to the Gulf of Mexico and ends 81 km away in a direct line on the eastern slopes of the Cofre de Perote at 3500 m, in central Veracruz, Mexico. Methods We studied the richness and composition of fern assemblages in 120 study plots at eight elevations at 20-3500 m in three forest types: natural forest (NF), disturbed forest (DF) subjected to timber extraction and grazing, and secondary forest (SF) regrown after total clearance 15-20 years ago. In addition, we measured microclimatic conditions in the three forest types at five elevations over a year. Results Fern richness peaked in humid montane forests at mid-elevations and was low in the dryer habitats at the ends of the gradient. Humid montane forests were most sensitive to disturbance, showing increases in mean annual temperatures by about 1°C and reduction in relative air humidity by about 20% in DF and SF compared to NF. This went along with a reduction of fern species richness by 5-60% and marked changes in species composition. In contrast, drought-deciduous forests at low elevations and coniferous forests at high elevations already had low humidity and high light intensity in NF and were less affected by human impact: Their microclimatic conditions and fern assemblages did not change markedly in DF and SF. Conclusions The conservation of much of the humidity-dependent biota (ferns and presumably also groups such as bryophytes and amphibians) in humid montane forests depends on the protection of natural fragments without human disturbance. In contrast, the naturally open forests at the ends of the gradient can be subjected to some exploitation while conserving much of their fern flora as long as a general forest structure is maintained. This article is protected by copyright. All rights reserved.

The use of non-timber forest products forms part of the strategy contributing to the well-being of populations near forest areas. Chamaedorea is one of the most important palm genera that is globally commercialized profitably for its attractive foliage used in floral decorations. In our study area located in the central region of Veracruz, Mexico we identified changes in tree cover between 1973 and 2017 using the normalized difference vegetation index (NDVI). We conducted plant surveys to identify tree species richness associated with the cultivation of C. elegans. We conducted semi-structured interviews with local palm producers to understand their perceptions regarding changes in tree cover in the study area and its association with the presence of the camedor palm. Soil cover patterns and vegetation index signatures indicated an increase in the forested area from 1973 to 2017 (after more than 43 years), with a 69% gain in secondary vegetation coverage with low NDVI values. This increase is associated with the cultivation of palm, since arboreal cover had previously been dominated by species traditionally used as shade for camedor cultivation. Tree diameters at breast height (DBH) were low, indicating young secondary forests with low recruitment and diversity in the understory suggestive of simplified species assemblages; most of the associated species were long-living pioneers and typical of the secondary forest favored by the palm producers. Producers mentioned they did not remove coffee because it is their main means of subsistence, and in combination with the palm, there is greater economic benefit. They also confirmed an increase in forest cover owing to the introduction of palm cultivars in the areas north and south of the study area. This was confirmed with the NDVI results, which detected the same spatial pattern. These changes resulted in the interruption of the processes of succession without the transition of secondary to old-growth forests. However, the canopy of the study area provides better environmental services than did the previously existing vegetation cover. This study showed the need for the assessment of non-timber forest products as key indicators of land use change and alterations in associated plant cover.

México is a cultural and biological megadiverse country with an increased anthropogenic pressure on its tropical landscapes. The study area was the ejido “Los Ídolos”, Misantla, Central Veracruz, Mexico. The main objective of this research was to identify how the woody plant diversity of agroforestry systems contributed to the cultural, economic, and subsistence security of local farmers. Five different agroforestry systems were identified: forest gardens (FG), home gardens (HG), plantation crop combination with perennial cultivates (PC), plantation crop combinations with annual cultivates (AC), and trees on pastures (TP). FG systems had the highest floristic diversity, followed by HG and TP. Interviews with farmers showed that FG, HG, and PC systems were important for maintaining cultural identity and secure subsistence needs, while PC and TP systems were important for improving the economic situation of farmers. The FG systems contained only native species, while the proportion of exotic plants differed among the other systems. Useful exotic plants were found in the HG system. This study demonstrated that agroforestry systems such as FG were not used to their full potential, despite their high diversity of useful plants. It is recommended that farmers—assisted by institutions and representatives of local product chains—conduct feasibility studies on the marketing and promotion of products derived from specific agroforestry systems.

Wild edible fruits are a complement to the diet, generate income, and contain cultural values for local populations. In Mexico, their presence is threatened mainly by deforestation. The purpose of ...

Deforestation and fragmentation are threats to the conservation of species and have consequences for ecosystem functions. The focus of this study was to elucidate forest cover change in the period of 1993 to 2014. Our study area is in the central region of Veracruz, Mexico. Land cover and land use classes for the Years 1993, 2000, and 2014 were derived from Landsat images applying supervised classification. Then, we quantified the net change in forest area, the loss of original forest area, and evaluated forest fragmentation using landscape metrics. Our results showed that the area covered by remnant forests decreased 57%. The annual net forest cover change rate for 1993 to 2000 was −0.44%; since then forest cover increased at a rate of 0.11% from 2000 to 2014. The decreasing total edge density and the mean proximity index during the entire period of the study indicate decreasing irregularity in the shape of remnant forest patches and a slight decrease of vulnerability to edge effects. Forest patches augm...